First trimester screening performance for preeclampsia using a combination of maternal factors and biomarkers was superior to the current recommended National Institute for Health and Care Excellence (NICE) guidelines, according to data published in Ultrasound in Obstetrics & Gynecology.
In this prospective multicenter cohort study, Screening Program for Preeclampsia (SPREE), researchers recruited women from 7 National Health Services maternity hospitals in England between April and December 2016. To be included, women had to be ≥18 years of age with a singleton pregnancy and a live fetus at the 11- to 13-week scan.
The primary comparison was the detection rate of screening recommended by the NICE guidelines vs a mini-combined test (a Bayes’ theorem-based method involving maternal factors, mean arterial pressure [MAP], and serum pregnancy-associated plasma protein-A [PAPP-A]) in predicting preeclampsia occurring at any gestational age, after adjustment for the effect of aspirin, for the same screen-positive rate determined by the NICE method.
The secondary comparisons included the detection rate of screening recommended by the NICE guidelines vs 3 Bayes’ theorem-based methods (maternal factors, MAP, and PAPP-A; maternal factors, MAP, and serum placental growth factor [PIGF]; and maternal factors, MAP, uterine artery pulsatility index [UtA-PI], and PIGF) in the prediction of preterm preeclampsia, categorized as requiring delivery earlier than 37 weeks. These biomarkers were chosen because the test can be performed without additional cost because all National Health Service maternity hospitals offer first trimester combined screening for trisomies, which includes the measurement of PAPP-A.
Of the 16,747 pregnancies, 473 developed preeclampsia and 142 developed preterm preeclampsia. The NICE method had a screen-positive rate of 10.3%, and the detection rate was 30.4% and 40.8% for all preeclampsia and preterm preeclampsia, respectively. The NICE guidelines recommend that women considered high risk for preeclampsia should be treated with aspirin from the first trimester until the end of the pregnancy, but the compliance rate was only 23%.
Meanwhile, the mini-combined test had a detection rate of 42.5%, which was superior to the NICE guidelines by 12.1% (95% CI, 7.9%-16.2%). In terms of screening for preterm preeclampsia by a combination of maternal factors and biomarkers, the detection rate was 53.5% (95% CI, 45.3%-61.7%) for MAP and PAPP-A, 69.0% (95% CI, 61.4%-76.6%) for MAP and PIGF, and 82.4% (95% CI, 76.1%-88.7%) for MAP, PIGF, and UtA-PI.
One potential limitation is that the researchers did not conduct a formal health economic assessment of the combined screening for preeclampsia. Although this assessment was beyond the study’s scope, it is currently being performed.
“The performance of screening for [preeclampsia] as currently recommended by NICE guidelines is poor and compliance with these guidelines is low,” the researchers concluded. “The performance of screening [was] substantially improved by a method combining maternal factors with biomarkers.”
Tan MY, Wright D, Syngelaki A, et al. Comparison of diagnostic accuracy of early screening for preeclampsia by NICE guidelines and a method combining maternal factors and biomarkers: results of SPREE [published online March 14, 2018]. Ultrasound Obstet Gynecol. doi:10.1002/uog.19039